1. Field of the Invention
This invention pertains to a portable freezer for preparation of sherbet, ice cream, and other frozen confections, of a type comprising a stationary bucket having an open top and holding ice, salt, and brine, a removable can holding confections being frozen, a removable head comprising horizontal arms bridging the open top of the bucket and a cover covering the can and its contents, a motor arranged to rotate the can within the bucket, and a dasher mounted within the can and beneath the cover so as to remain relatively stationary as the can is rotated. Such portable freezers are commonplace in households.
2. Brief Description of the Prior Art
It is conventional for a user to operate a portable freezer of the type noted above until the contents of the can have been frozen to such firmness that relative rotation of the can and the dasher is impeded, whereupon the motor begins to stall and the user must take positive steps to disable the motor. Such a freezer is exemplified in U.S. Pat. No. 3,087,708 to W. M. Sims.
As exemplified in U.S. Pat. No. 1,449,458 to L. A. Sutermeister, it is known for electrical loads on the motor of a power driven ice cream freezer to be monitored, by means of an ammeter. However, such a scheme is not suitable for a portable freezer to be used in households, because the ammeter must be calibrated for each mixture, composition, or recipe.
As exemplified in U.S. Pat. No. 3,926,414 to P. Tanguy and U.S. Pat. No. 4,009,588 to P. Tanguy et al., it is known to sense emanated heat from the motor of a portable freezer of similar utility, to open a circuit so as to disable the motor when high temperatures reflecting heavy loads on the motor are sensed, and to actuate an alarm when the motor is disabled Cf. U.S. Pat. No. 1,880,021 to G. C. McCauley et al.
As exemplified in U.S. Pat. No. 2,541,814 to N. F. Gaddini, it is known to provide a portable freezer, of a type comprising a similar can but having no stationary bucket for ice, salt, and brine, and needing to be placed in a freezing locker or other such enclosure at low temperature, with a dasher, which is permitted limited rotation but restrained by a spring, and with a switch, which is linked to the dasher and arranged to disable the motor upon sufficient rotation of the dasher. Cf. U.S. Pat. No. 3,407,618 to J. N. Mullins, Sr., and U.S. Pat. No. Re 27,019 to C. B. Harber.
Various other mechanisms, which respond to the firmness of confections being frozen in various types of freezers employing various types of dashers, blades, or paddles, are exemplified in U.S. Pat. No. 1,763,567 to A. T. Simmons et al., U.S. Pat. No. 2,272,614 to L. W. Reinken et al., U.S. Pat. No. 2,552,648 to A. J. Tacchella, U.S. Pat. No. 2,793,505 to D. M. Finch, U.S. Pat. No. 3,046,755 to R. Y. Sale, U.S. Pat. No. 3,108,449, and U.S. Pat. No. 3,695,051 to W. B. Hunt. Some of these freezers are not suitable for use in households.
It would be desirable if the user of a portable freezer, of the type to which this invention pertains, could have some way simply, progressively, and visually to monitor the firmness of the contents being frozen, so as to be able to prepare soft confections, as well as firm confections, of a variety of different recipes yielding optimum results at different firmnesses. There should be no need for the user to calibrate any components for different recipes.